Vehicle-to-vehicle communication (Car-to-Car communication, C2C) is the direct interchange of information between moving vehicles. Functional radio networks and new applications can be implemented by this mobile communication. This includes timely information about road and traffic conditions, such as black ice, aquaplaning, accidents or stationary vehicles. In this safety-relevant application, the appropriate vehicle sends the indication of the hazard location together, for example, with the data from the navigation system. Further information relating to the traffic flow may be information about traffic-light phases, stop-and-go journeys or stationary approach to and stopping at road works. Such vehicle-to-vehicle communication may also include searching for car parks, and information about free car-park capacities.
Furthermore, vehicle-to-X communication (car-to-X communication, C2X) is also known as direct interchange of the information between a moving vehicle and a further subscriber, for example an infrastructure. By way of example, this allows telephone data, WLAN uses or UMTS signals to be transmitted from the vehicle, or else to the vehicle. Furthermore, in present-day traffic, the connection between the vehicle and satellites is playing an increasingly more important role for user navigation. In this case, the communication subscribers who are connected to the vehicle for communication reside at widely different locations.